Data storage systems commonly have one or more data storage media and one or more elements (for example, read/write heads) that communicate with the data storage media to store and retrieve data. Data storage media may be magnetic storage media, optical storage media, etc. Magnetic storage media such as magnetic discs may comprise a substrate over which a non-magnetic underlayer, a magnetic layer and a protective overcoat are deposited using a suitable technique.
A plasma enhanced chemical vapor deposition (PECVD) technique may be used to deposit the protective overcoat. This technique may employ a deposition source having a filament for emitting electrons.